The present invention relates to an air cooling system to be used in connection with a preform molding machine which makes advantageous use of air amplifiers to cool the molded preforms and to a method of using same.
Index type injection molding machines with part cooling features at a variety of stations are shown in U.S. Pat. Nos. 5,728,409; 5,830,404; 5,750,162; and 5,817,345. The cooling of preforms on an index block using a part removal and cooling robot is shown in copending U.S. patent applications Ser. No. 09/167,699, filed Oct. 7, 1998, to Ing et al. entitled Cooling Device Attached to Index Machine; Ser. No. 09/215,819, filed Dec. 18, 1998, to Kutalowski entitled Cooling Device Attached to Index Machine; Ser. No. 09/261,880, filed Mar. 3, 1999, to Domodossola et al. entitled Turret Cooling Block for an Index Machine; and Ser. No. 09/263,393, filed Mar. 5, 1999, to Kozai et al. entitled Cooling Device Attached to Index Machine, all of which are assigned to the assignee of the instant patent application, and all of which are incorporated by reference herein. None of these patents and patent applications however teach the use of an air amplifier or applying different cooling conditions at different index block stations.
Cooling preforms by means of blowing air on their surfaces after the preform has been removed from a mold is shown in Japanese patent publication 7-171888 to Sumitomo. Further, U.S. Pat. No. 5,232,715 to Fukai teaches blowing air over the outside of a preform while it is held on a cooling mandrel. In both of these prior art examples, the preforms have been removed from the mold and are being cooled in a downstream piece of equipment. In order for the preforms to be removed from the mold without damage, sufficient cooling must take place in the mold to allow damage free ejection. Thus, a cycle time penalty has been accepted in order to do downstream cooling.
U.S. Pat. No. 4,449,913 to Krishnakumar shows blowing air over the outside of preforms while they are still on injection molding cores that are mounted on a turret block. The air blowing nozzles are at a fixed distance from the preforms. The Krishnakumar patent lacks any teaching of an air amplifier or how different cooling effects can be achieved at different areas of a preform surface.